Apparatus to which this invention relates is used to deliver bulk material to a processing stage at a constant, predetermined feedrate. Material from a supply hopper is deposited on a pivotally-mounted endless belt, the linear speed of the belt being continuously adjusted to compensate for deviations between the material carried by the belt and a predetermined, desired weight.
Material of fibrous or stringy form is difficult to feed as it has a variable bulk density caused by moisture absorption and, also, such material tends to clump together and matte even under controlled moisture conditions. Feeders as made heretofore have not been satisfactory in achieving a uniform delivery of the fibrous material from a supply hopper to the weigh belt, thereby making it impossible to maintain a precise, constant material feedrate.
Apparatus made in accordance with this invention utilizes a rotating rake for movement of the material from the hopper to a discharge opening spaced above an endless belt. The material delivered to the belt has a fairly uniform bulk density and the rate at which such material is deposited on the belt exceeds the rate at which the belt transports material away from said discharge opening. The excess material is returned to the hopper by the rotating rake, thereby to maintain a uniform heighth of the material transported by the belt.